Method, terminal, and non-transitory computer readable medium for downlink data transmission based on scheduling of physical downlink shared channels (PDSCHs)

ABSTRACT

A method for downlink data transmission and related products are provided. The method includes: a terminal receives downlink control information (DCI) for scheduling multiple physical downlink shared channels (PDSCHs), wherein the DCI contains transmission configuration indicator (TCI) state indication; and the terminal determines a TCI state which is applied to each of the multiple PDSCHs according to at least one TCI state indicated by the TCI state indication.

CROSS REFERENCE TO RELATED APPLICATION(S)

This application is a continuation of International Application No.PCT/CN2019/075232, filed on Feb. 15, 2019, the entire disclosure ofwhich is incorporated herein by reference.

TECHNICAL FIELD

This disclosure relates to the field of communication technology, inparticular to methods for downlink data transmission and relatedproducts.

BACKGROUND

At present, the transmission configuration indicator (TCI) stateindication field in downlink control information (DCI) in a wirelesscommunication system can only indicate a limited number of TCI states,the number of physical downlink shared channel (PDSCH) repetition, onthe other hand, can be large. The terminal is unable to determine whichTCI state is used for PDSCH reception for each of multiple PDSCHscarrying the same data and therefore, the expected diversity gain cannotbe obtained.

SUMMARY

According to a first aspect, a method for downlink data transmission isprovided. The method includes: receiving, by a terminal, DCI forscheduling multiple PDSCHs, where the DCI contains TCI state indication;and determining, by the terminal, a TCI state which is applied to eachof the multiple PDSCHs according to at least one TCI state indicated bythe TCI state indication.

According to a second aspect, a terminal is provided. The terminal hasfunctions of realizing the behavior of the terminal in the above methoddesign. The functions can be realized by hardware or by executingcorresponding software with hardware. The hardware or software includesone or more modules corresponding to the above functions. In onepossible design, the terminal includes a processor, which is configuredto enable the terminal to perform the corresponding functions in theabove method. The terminal may further include a transceiver, which isconfigured to enable communication between the network device and theterminal. The terminal may further include a memory, which is coupledwith the processor and configured to store necessary programinstructions and data for the terminal.

According to a third aspect, a computer readable storage medium isprovided. The computer readable storage medium is configured to storecomputer programs for electronic data interchange, where the computerprograms are operable with a computer to perform all or part of thesteps of the method of the first aspect.

BRIEF DESCRIPTION OF THE DRAWINGS

The following will briefly introduce the drawings to be used in thedescription of the application or the related art.

FIG. 1a is a diagram illustrating a system architecture of a wirelesscommunication system provided in implementations of the disclosure.

FIG. 1b is a diagram illustrating a process of downlink beam managementprovided in implementations of the disclosure.

FIG. 1c is a diagram illustrating a TCI state configuration method forPDSCH.

FIG. 1d is a diagram illustrating slot-based PDSCH repetition.

FIG. 1e is a diagram illustrating TRP-based PDSCH repetition.

FIG. 2 is a schematic flowchart of a method for downlink datatransmission.

FIG. 3 is a schematic flowchart of another method for downlink datatransmission.

FIG. 4a is a schematic flowchart of another method for downlink datatransmission.

FIG. 4b is a diagram illustrating one-to-one correspondence-based TCIstate determination.

FIG. 4c is a diagram illustrating multi-slot repetition of PDSCH, whereN=8.

FIG. 4d is diagram illustrating another multi-slot repetition of PDSCH,where N=8.

FIG. 5a is a schematic flowchart of another method for downlink datatransmission.

FIG. 5b is a diagram illustrating multi-transmission occasion repetitionof PDSCH, where M=3, N=8.

FIG. 5c is a diagram illustrating multi-transmission occasion repetitionof PDSCH, where X=3, N=4.

FIG. 6 is a schematic flowchart of another method for downlink datatransmission.

FIG. 7 is a structural diagram illustrating a network device accordingto implementations.

FIG. 8 is a structural diagram illustrating a terminal according toimplementations.

FIG. 9 is a block diagram illustrating functional units of a networkdevice.

FIG. 10 is a block diagram illustrating functional units of a terminal.

DETAILED DESCRIPTION

Technical solutions in implementations of the disclosure will now bedescribed in combination with the drawings.

FIG. 1a illustrates a wireless communication system. The wirelesscommunication system is operable at a high frequency band, and can be afuture evolution of the 5th generation (5G) system, a new radio (NR)system, a machine to machine (M2M) system, etc. As illustrated in FIG.1a , the wireless communication system 100 may include one or morenetwork devices 101, one or more terminals 103, and a core network (CN)device 105. The network device 101 may be a base station, which cancommunicate with one or more terminals, or communicate with one or morebase stations having some terminal functions, such as communicationbetween a macro base station and a micro base station (such as an accesspoint (AP)). The base station may be a base transceiver station (BTS) ina time division synchronous code division multiple access (TD-SCDMA)system, an evolutional Node B (eNB) in a long-term evolution (LTE)system, or a gNB in the 5G system or NR system. The base station canalso be an AP, a transmission point (TRP), a central unit (CU) or othernetwork entities, and may has all or part of the functions of the abovenetwork entities. The CN device 105 includes CN side devices such as aserving gateway (SGW). The terminal 103 may be distributed across theentire wireless communication system 100, and may be stationary ormobile. In some implementations, the terminal 103 may be a mobile devicesuch as a smart phone, a mobile station, a mobile unit, a M2M terminal,a wireless unit, a remote unit, a user agent, a user equipment (UE), amobile client, etc.

The wireless communication system 100 illustrated in FIG. 1a is only fora clearer explanation of the technical solution of the disclosure, anddoes not constitute any limitation of the disclosure. With the evolutionof network architecture and the emergence of new service scenarios, thetechnical solution provided herein is also applicable to similartechnical problems.

The related technologies involved in the disclosure are described below.

At present, in a NR system design, such as the downlink (DL) beammanagement process illustrated in FIG. 1b , the network device can usean analog beam to transmit PDSCH. In FIG. 1b , a channel stateinformation reference signal (CSI-RS) is taken as an example, and “RSRP”refers to reference signal received power. Before analog beamforming,the network device needs to determine the beam to be used through thedownlink beam management process. The downlink beam management can bebased on CSI-RS or synchronization signal block (SSB). Specifically, thenetwork device transmits multiple SSB resources or multiple CSI-RSresources for beam management, based on which the terminal can performdetection, select the SSB resource(s) or CSI-RS resource(s) with thebest quality, and report the index of the SSB resource(s) selected orthe index of CSI-RS resource(s) selected together with the correspondingRSRP to the network device. According to the report received from theterminal, the network device determines an optimal SSR resource or anoptimal CSI-RS resource, and determines a transmit beam used by theoptimal SSR resource or the optimal CSI-RS resource as a transmit beamfor downlink transmission, to transmit downlink control channel or datachannel. Before transmitting the downlink control channel or datachannel, the network device will indicate a corresponding QCL referencesignal to the terminal through a TCI state, such that the terminal canuse a receiving beam previously used for receiving the QCL referencesignal to receive a corresponding downlink control channel or datachannel.

In the NR system, during downlink transmission of a QCI indication, thenetwork device can configure a TCI state for each downlink signal ordownlink channel to indicate a QCL reference signal corresponding to atarget downlink signal or a target downlink channel, such that theterminal can receive the target downlink signal or the target downlinkchannel based on the QCL reference signal. One TCI state may furtherinclude: TCI state ID for identifying a TCI state; QCL information 1;QCL information 2, where QCL information may further include: QCL type,which may be one of Type A, Type B, Type C, or Type D; QCL referencesignal configuration, including cell ID of a cell where the referencesignal is located, band width part (BWP) ID, and reference signal ID(may be CSI-RS resource ID or SSB index). At least one of QCLinformation 1 and QCL information 2 should take the QCL type of Type A,Type B, or Type C, and the other one of QCL information 1 and QCLinformation 2 (if configured) should take the QCL type of Type D.Different QCL types are defined as follows:

‘QCL-TypeA’: {Doppler shift, Doppler spread, average delay, delayspread}

‘QCL-TypeB’: {Doppler shift, Doppler spread}

‘QCL-TypeC’: {Doppler shift, average delay}

‘QCL-TypeD’: {Spatial Rx parameter}

If the network device configures, through the TCI state, the QCLreference signal of the target downlink channel as the reference SSBresource or the reference CSI-RS resource, and the QCL type as Type A,Type B, or Type C, the terminal can assume that the target downlinksignal has the same target large-scale parameter as the reference SSBresource or the reference CSI-RS resources, and thus can use the samecorresponding receive parameter for receiving. The target large-scaleparameter is determined according to the QCL type. Similarly, if thenetwork device configures, through the TCI state, the QCL referencesignal of the target downlink channel as the reference SSB resource orthe reference CSI-RS resource, and the QCL type as Type D, the terminalcan use a receive-beam, which is the same as that used for receiving thereference SSB resource or reference CSI-RS resource, for target downlinksignal receiving. Generally, the target downlink channel and thereference SSB resource or reference CSI-RS resource thereof aretransmitted by the same TRP, the same panel, or the same beam at thenetwork device. If the TRP, the panel, or beam for transmission of twodownlink signals or downlink channels are different, different TCIstates are usually configured.

For a downlink control channel, the TCI state can be indicated throughradio resource control (RRC) signaling, or can be indicated through RRCsignaling and media access control (MAC) signaling. For a downlink datachannel, a set of available TCI states is indicated through RRCsignaling, and some TCI states in the set are activated through MACsignaling. Finally, one or two TCI states are indicated from theactivated TCI states through a TCI state indication field in DCI, andused for DCI scheduled PDSCH. In the TCI state configuration method forPDSCH in FIG. 1c , the network device indicates N TCI states through RRCsignaling, indicates K activated TCI states through MAC signaling, andindicates one or two TCI states from the K activated TCI states throughRRC signaling, where N and K are positive integers and N≥K.

In the NR system, in order to improve the transmission reliability ofPDSCH, repetition of PDSCH is introduced, that is, PDSCHs carrying thesame data are transmitted through different slots/TRPs/redundancyversions for many times, thus the diversity gain can be obtained and theprobability of false detection (BLER) can be reduced. Specifically,PDSCH repetition can be transmitted across multiple slots (in FIG. 1d ,slots and physical downlink control channel (PDCCH) are illustrated) ormultiple TRPs (in FIG. 1e , Acknowledge/Non-Acknowledge (ACK/NACK) areillustrated). For multi-slot based repetition, one DCI can schedulePDSCHs carrying the same data to be transmitted across consecutive slotsand use the same frequency domain resource. For multiple TRPs basedrepetition, PDSCHs carrying the same data are transmitted from differentTRPs and use different beams, here, more than one TCI state is indictedin one DCI. The multi-TPR based repetition can be combined with themulti-slot based repetition, as such, PDSCH repetition is transmittedacross consecutive slots, and at different slots, PDSCH repetition istransmitted from different TRPs.

At present, the TCI state indication field in DCI can only indicate verylimited number of TCI states, the number of PDSCH repetition, on theother hand, can be large. The terminal is unable to determine which TCIstate is used for PDSCH reception for each of multiple PDSCHs carryingthe same data, and therefore the expected diversity gain cannot beobtained.

Taking the above into consideration, implementations of the disclosureare given below with reference to the accompanying drawings.

FIG. 2 illustrates a method for downlink data transmission, which isapplicable to the communication system given above. The method isimplemented as follows.

At block 201, a network device determines a TCI state which is appliedto (in other words, corresponds to) each of multiple PDSCHs according toat least one of a beam and a TRP used for transmitting each PDSCH.

The term “multiple PDSCHs” may refer to PDSCH repetitions, the term “then-th PDSCH” in the multiple PDSCHs may refer to the n-th PDSCHrepetition. The above definition is applicable to the whole disclosureand will not be repeated hereinafter. The TCI state can be determinedaccording to the TRP, according to the beam, or according to the TRP andthe beam.

After determining the TCI state which is applied to each PDSCH, thenetwork device can: generate TCI state indication according to the TCIstate which is applied to each PDSCH; generate, according to the TCIstate indication, DCI for scheduling the multiple PDSCHs; transmit theDCI, the DCI is used for the terminal to determine the TCI state whichis applied to each PDSCH from at least one TCI state indicated by theTCI state indication.

In one possible implementation, the method further includes: the networkdevice transmits DCI for scheduling multiple PDSCHs, the DCI containsTCI state indication for indicating the TCI state which is applied toeach PDSCH, and the multiple PDSCHs carry the same data.

The expression of “the multiple PDSCHs carry the same data” may refer tothat the multiple PDSCHs adopt the same HARQ process, or the multiplePDSCHs transmit the same transport block (TB). The above definition isapplicable to the whole disclosure and will not be repeated hereinafter.

The term “same data” may refer to the same data source bit, that is, thedata bits before channel coding are the same. The data bits afterchannel coding can be different.

As such, the terminal can determine the TCI state which is applied toeach of multiple PDSCHs (or multiple repetitions of one PDSCH)transmitting the same data from multiple TCI states configured by thenetwork device, and can switch flexibly between multiple TCI states. Thecommunication system can obtain significant diversity gain with lesssignaling overhead, and the reliability of downlink PDSCH transmissioncan be improved.

In one possible implementation, in the multiple PDSCHs, PDSCHstransmitted by using different beams or by different TRPs correspond todifferent TCI states, and/or, PDSCHs transmitted by using a same beam orby a same TRP correspond to a same TCI state.

In one possible implementation, the multiple PDSCHs correspond tomultiple TCI states.

In one possible implementation, after transmitting the DCI forscheduling the multiple PDSCHs, the method further includes: the networkdevice transmits the multiple PDSCHs according to the beam or the TRPused for transmitting each of the multiple PDSCHs.

Accordingly, at the terminal side, after receiving the DCI, the terminalcan determine the TCI state which is applied to each PDSCH according tothe at least one TCI state indicated by the TCI state indication in theDCI, and further determine the correspondence between beams/TRPs, TCIstates, and PDSCHs, to receive multiple PDSCHs.

FIG. 3 illustrates a method for downlink data transmission according toanother implementation, which is applicable to the above communicationsystem. The method includes the following.

At block 301, the terminal device receives DCI for scheduling multiplePDSCHs, where the DCI contains TCI state indication.

The DCI is generated at the network device side by: determining a TCIstate which is applied to each of multiple PDSCHs according to at leastone of a beam and a TRP used for transmitting each PDSCH; generating theTCI state indication according to the TCI state which is applied to eachPDSCH; generating the DCI for scheduling the multiple PDSCHs accordingto the TCI state indication.

At block 302, the terminal determines the TCI state which is applied toeach of the multiple PDSCHs from the at least one TCI state indicated bythe TCI state indication.

In one possible implementation, the multiple PDSCHs carry the same data.

In one possible implementation, the multiple PDSCHs are transmittedacross consecutive slots, across consecutive PDSCH transmissionoccasions, or in a single slot.

In one possible implementation, the multiple PDSCHs are transmittedbased on at least one of: a same demodulation reference signal (DMRS)port, a same orthogonal frequency division multiplexing (OFDM) symbol,or a same modulation and coding scheme (MCS) and a same hybrid automaticrepeat request (HAQR) process.

For example, the multiple PDSCHs are transmitted based on the same DMRSport, the same OFDM symbol, or the same MCS and the same HAQR process.

Alternatively, the multiple PDSCHs can be transmitted based on the samefrequency domain resource.

In one possible implementation, the at least one TCI state is multipleTCI states.

In one possible implementation, the terminal determines the TCI statewhich is applied to each of the multiple PDSCHs from the at least oneTCI state indicated by the TCI state indication as follows: the terminaldetermines the TCI state which is applied to each of the multiple PDSCHsfrom the at least one TCI state according to a rule agreed with anetwork device.

As such, according to the agreed rule, the terminal can determine theTCI state which is applied to each of the multiple PDSCHs carrying thesame data (or multiple repetitions of one PDSCH) from multiple TCIstates configured by the network device, since the rule is specified inthe protocol, the terminal can determine the TCI state which is appliedto each PDSCH without extra signaling overhead.

In one possible implementation, the number of the multiple PDSCHs is N,the number of the at least one TCI state is K, where N and K arepositive integers.

In one possible implementation, the rule includes at least one of: themultiple PDSCHs are in one-to-one correspondence with the at least oneTCI state, when N=K; the first N TCI sates in the at least one TCI statecorrespond to the N PDSCHs, and the N PDSCHs are in one-to-onecorrespondence with the first N TCI states, when N<K; the n-th PDSCH inthe multiple PDSCHs corresponds to the k-th TCI state in the at leastone TCI state, and k=[(n−1) mod K+1], when N>K; the n-th PDSCH in themultiple PDSCHs corresponds to the k-th TCI state in the at least oneTCI state, and k=┌n/m┐, when N=K*m and m is an integer greater than 1.

In this implementation, with aid of the rule agreed, on the one hand,the diversity gain of multiple TRPs or multiple beams can be obtained inthe first few transmissions, so that the terminal can detect the PDSCHfaster and reduce the delay of correct transmission; on the other hand,complexity of the terminal is taken into consideration, and the numberof switching to receiving beam is reduced as much as possible.

In one possible implementation, the terminal determines the TCI statewhich is applied to each of the multiple PDSCHs from the at least oneTCI state indicated by the TCI state indication as follows: the terminaldetermines the TCI state which is applied to each of the multiple PDSCHsfrom the at least one TCI state indicated by the TCI state indicationaccording to an index sequence configured through higher layersignaling.

As such, according to the index sequence configured by the networkdevice through higher layer signaling, the terminal can determine theTCI state which is applied to each of the multiple PDSCHs carrying thesame data (or multiple repetitions of one PDSCH) from multiple TCIstates configured by the network device and can switch flexibly betweenmultiple TCI states, such that the communication system can obtainsignificant diversity gain with little signaling overhead, thusimproving the reliability of downlink PDSCH transmission.

In one possible implementation, each index value in the index sequenceis used to indicate an index of a TCI state in the at least one TCIstate.

In one possible implementation, the index sequence has a length equal tothe number of the multiple PDSCHs, and TCI states indicated by the indexsequence are in one-to-one correspondence with the multiple PDSCHs. Theterminal determines the TCI state which is applied to each of themultiple PDSCHs from the at least one TCI state according to the indexsequence configured through higher layer signaling as follows: theterminal determines the TCI state which is applied to each of themultiple PDSCHs according to the TCI states indicated by the indexsequence and the correspondence.

In one possible implementation, the index sequence has a length equal tothe number of the at least one TCI state or equal to a fixed value, TCIstates indicated by the index sequence correspond to the multiple PDSCHscircularly, or the first N TCI states in the TCI states indicated by theindex sequence are in one-to-one correspondence with the multiplePDSCHs, where Nis the number of the multiple PDSCHs. The terminaldetermines the TCI state which is applied to each of the multiple PDSCHsfrom the at least one TCI state according to the index sequenceconfigured through higher layer signaling as follows: the terminaldetermines the TCI state which is applied to each of the multiple PDSCHsaccording to the TCI states indicated by the index sequence and thecorrespondence.

In one possible implementation, the fixed value is 2.

In one possible implementation, the n-th PDSCH in the multiple PDSCHscorresponds to a TCI state with an index value m in the at least one TCIstate, wherein m is the k-th index value in the index sequence, k=[(n−1)mod K+1], and K represents the length of the index sequence.

In one possible implementation, the terminal determines the TCI statewhich is applied to each of the multiple PDSCHs from the at least oneTCI state indicated by the TCI state indication as follows: the terminaldetermines the TCI state which is applied to each of the multiple PDSCHsfrom the at least one TCI state according to a redundancy versionconfiguration(s) of the multiple PDSCHs.

In this implementation, based on the redundancy version configurationused for PDSCH transmission, the terminal can determine the TCI statewhich is applied to each of the multiple PDSCHs carrying the same data(or multiple repetitions of one PDSCH) from multiple TCI statesconfigured by the network device, since the redundancy versionconfiguration is known to the terminal, the terminal can determine theTCI state which is applied to each PDSCH without extra signalingoverhead.

In one possible implementation, the terminal determines the TCI statewhich is applied to each of the multiple PDSCHs from the at least oneTCI state according to the redundancy version configuration(s) of themultiple PDSCHs as follows: the terminal determines an index sequencecorresponding to redundancy version indication contained in the DCIaccording to the redundancy version indication, and determines the TCIstate which is applied to each of the multiple PDSCHs from the at leastone TCI state according to the index sequence; or the terminaldetermines the TCI state which is applied to each of the multiple PDSCHsaccording to a redundancy version used by each of the multiple PDSCHsand a correspondence between redundancy versions and TCI states.

In one possible implementation, the method further includes: theterminal detects the multiple PDSCHs according to the TCI state which isapplied to each of the multiple PDSCHs.

In one possible implementation, the terminal detects the multiple PDSCHsaccording to the TCI state which is applied to each of the multiplePDSCHs as follows: the terminal detects each of the multiple PDSCHs bydetecting large-scale parameters used by a quasi co-location (QCL)reference signal contained in the TCI state which is applied to each ofthe multiple PDSCHs, according to the QCL reference signal and a QCLtype contained in the TCI state which is applied to each of the multiplePDSCHs, where the large-scale parameter is a large-scale parameterindicated by the QCL type.

Implementations of the disclosure will be described in combination withspecific scenarios.

FIG. 4a illustrates a method for downlink data transmission. The methodis applicable to the above communication system and includes thefollowing operations.

At block 401, the network device decides to transmit PDSCH with K TRPs,and repetition of the PDSCH is performed across multiple slots toimprove transmission reliability. The number (N) of repetition isnotified to the terminal through higher layer signaling, N=2, 4, 8, andK is a positive integer.

K=1 or K=2. The higher layer signaling can be RRC signaling.

At block 402, the network device determines a beam(s) used fortransmitting the PDSCH by the K TPRs, and determines K TCI states, here,the TCI states can be determined according to the TRP.

At block 403, the network device transmits downlink DCI for schedulingmultiple PDSCHs which are transmitted repeatedly. The DCI contains TCIstate indication for indicating K TCI states, and the multiple PDSCHscarry the same data.

At block 404, the terminal receives the number (N) of PDSCH repetitionwhich is notified by the network device through RRC signaling, thenumber N can be configured through RRC parameterpdsch-AggregationFactor.

At block 405, the terminal receivers the downlink DCI for scheduling theN PDSCHs, where the DCI contains TCI state indication for indicating theK TCI states.

The TCI state indication is for indicating the K TCI states form P TCIstates indicated in advance by RRC signaling or MAC control element(CE), where P is an integer and P≥K.

In this implementation, it is assumed that the multiple PDSCHs aretransmitted across consecutive slots. The multiple PDSCHs occupy thesame physical resource across the consecutive slots. This implementationis also applicable to consecutive transmission occasions based PDSCHrepetition.

The PDSCH can be transmitted based on the same scheduling information,such as the same number of transmission layers, the same DMRS port andDMRS location, the same frequency resource, the same OFDM symbol, or thesame MCS and the same HARQ process.

At block 406, the terminal determines the TCI state which is applied toeach of the multiple PDSCHs according to the K TCI states indicated bythe TCI state indication.

In one implementation, the terminal determines the TCI state which isapplied to each PDSCH from the K TCI states according to a rule agreedwith the network device. The following will describe how to determinethe TCI state which is applied to each PDSCH, with K=2. The number ofmultiple PDSCHs is N, and N=2, 4, 8, the index sequence corresponding tothe K TCI states is {TCI state 0, TCI state 1}, that is, the indexes ofthe two TCI states are 0 and 1 respectively.

Case 1: N=K=2, as illustrated in FIG. 4b , the two PDSCHs and the twoTCI states are in one-to-one correspondence, that is, the first PDSCH ofthe two PDSCHs corresponds to the first TCI state in the two TCI states,and the second PDSCH of the two PDSCHs corresponds to the second TCIstate in the two TCI states.

Case 2: N>K, the TCI state which is applied to each PDSCH can bedetermined in one of the following manners.

Manner 1: The K TCI states are circularly applied to the N PDSCHs as awhole. Specifically, the n-th PDSCH in the N PDSCHs corresponds to thek-th TCI state in the K TCI states, where k=[(n−1) mod K+1].

For example, if N=2, then the index sequence of the TCI statescorresponding to the two PDSCHs is {0, 1}; if N=4, then the indexsequence of the TCI states corresponding to the four PDSCHs is {0, 1, 0,1}; if N=8, then as illustrated in FIG. 4c , the index sequence of theTCI states corresponding to the eight PDSCHs is {0, 1, 0, 1, 0, 1, 0,1}.

The multiple PDSCHs pool the multiple TCI states and then repeats,therefore can obtain diversity gain of multiple slots or multiple beamsin the first few transmission. As such, the terminal can detect thePDSCH faster and the latency of correct transmission can be reduced.

Manner 2: The K TCI states are applied to the N PDSCHs in sequence, thatis, the first TCI state is applied to the N PDSCHs, then the second TCIstate is applied to the N PDSCHs, and so on, until the K-th TCI state.Specifically, N=m*K(m>1), the n-th PDSCH in the N PDSCHs corresponds tothe k-th TCI state in the K TCI states, where k=┌n/m┐. For example, K=2,then the first TCI state applies to the first half of the multiplePDSCHs and the second TCI state applies to the second half of themultiple PDSCHs.

For example, if N=2, then the index sequence of the TCI statescorresponding to the two PDSCHs is {0, 1}; if N=4, then the indexsequence of the TCI states corresponding to the four PDSCHs is {0, 0, 1,1}; if N=8, then as illustrated in FIG. 4d , the index sequence of theTCI states corresponding to the eight PDSCHs is {0, 0, 0, 0, 1, 1, 1,1}.

If different TCI states can indicate different receive-beams, then theterminal does not have to switch between receive-beams frequently, sothe complexity of operations of the terminal can be reduced.

The above Manner 1 and Manner 2 can be used in combination. For example,if N=4, then the index sequence of TCI states corresponding to the fourPDSCHs is {0, 1, 1, 0}; if N=8 and K=2, then the index sequence of TCIstates corresponding to the eight PDSCHs is {0, 0, 1, 1, 1, 1, 0, 0} or{0, 1, 1, 0, 0, 1, 1, 0}. In this way, both the diversity gain and thereceiving beam switching frequency of the terminal are considered, whichensures the diversity gain and low complexity.

At block 407, the terminal detects the multiple PDSCHs according to theTCI state which is applied to each of the multiple PDSCHs.

Suppose a first PDSCH in the multiple PDSCHs corresponds to a first TCIstate, and the first TCI state contains QCL Type A and a correspondingCSI-RS resource ID, where the first CSI-RS resource ID indicates a firstCSI-RS resource. The terminal assumes that the first PDSCH and a channelthrough which the signal on the first CSI-RS resource passes have thesame Doppler shift, Doppler spread, average delay, and delay expansion.Here, the terminal can adopt the {Doppler shift, Doppler spread, averagedelay, and delay expansion} used to receive the CSI-RS on the firstCSI-RS resource to detect the first PDSCH.

For each of the multiple PDSCHs, detection can be performed by theterminal according to the TCI state of the PDSCH and the operationsdescribed above.

FIG. 5a illustrates a method for downlink data transmission, which isapplicable to the above communication system and includes the followingoperations.

At block 501, the network device decides to transmit PDSCH by K TRPs,and repetition of the PDSCH is performed across multiple mini-slots toimprove transmission reliability. The number (N) of repetition isnotified to the terminal through higher layer signaling, N=2, 4, 8, andK is a positive integer.

At block 502, the network device determines a beam(s) used fortransmitting the PDSCH by the K TPRs. The network device can use L beamsto transmit the PDSCH on each TRP, therefore, the beam used to transmitthe PDSCH by the network device corresponds to M=K*L TCI states, here,the TCI state is determined according to the TRP and the beam.

At block 503, the network device transmits downlink DCI for schedulingmultiple PDSCHs which are transmitted repeatedly. The DCI contains TCIstate indication for indicating M TCI states, and the multiple PDSCHscarry the same data.

At block 504, the terminal receives the downlink DCI for scheduling theN PDSCHs, where the DCI contains TCI state indication.

Before block 504, the terminal may receive the number (N) of PDSCHrepetition which is notified by the network device through RRCsignaling. Alternatively, the terminal may determine the number (N) ofPDSCH repetition based on the indication in the DCI.

The TCI state indication is for indicating M TCI states form P TCIstates indicated by RRC signaling or MAC control element (CE), where Pis an integer and P≥M.

Here, in case that the N PDSCHs are transmitted across N PDSCHtransmission occasions, one PDSCH transmission occasion may also bereferred to as a mini-slot.

In one possible implementation, the multiple PDSCHs occupy the samephysical resource across the consecutive PDSCH transmission occasions.

In one possible implementation, each of the consecutive PDSCHtransmission occasions occupies the same number of OFDM symbols, and thelength of each PDSCH transmission occasion may be less than one slot.

The N consecutive PDSCH transmission occasions may be in one slot, ormay across multiple slots.

In one possible implementation, the DCI may indicate the resourcelocation of the first PDSCH transmission occasion, and othertransmission occasions occupy the subsequent OFDM symbols in turn.

The method in this implementation is also applicable to consecutive Nslots based PDSCH repetition.

The multiple PDSCHs can be transmitted based on the same schedulinginformation, for example, the same number of transmission layers, thesame DMRS port and the same DMRS location, or the same OFDM symbol andthe same HARQ process.

At block 505, the terminal determines the TCI state which is applied toeach of the multiple PDSCHs according to the M TCI states indicated bythe TCI state indication.

Specifically, the terminal determines the TCI state of each PDSCH from MTCI states according to an index sequence configured by the networkdevice through higher layer signaling. In the following, the number ofthe multiple PDSCHs is N.

Each index value in the index sequence is used to indicate the index ofa TCI state in the M TCI states. The TCI state can be applied to one ormore PDSCHs in the multiple PDSCHs.

The index sequence can be indicated in one or more of the followingmanners.

Manner 1: The length of the index sequence is N, and N TCI statesindicated by the index sequence are in one-to-one correspondence withthe N PDSCHs. The terminal determines, from the M TCI states, the targetTCI state corresponding to the n-th index value in the index sequence asthe TCI state of the n-th PDSCH in the N PDSCHs.

For example, M=2 and N=4, the candidate index sequence may be {0, 1, 0,1}, {0, 0, 1, 1}, {0, 0, 0, 0}, {1, 1, 1, 1}. The network device caninform the terminal of the index sequence used for current PDSCHtransmission through higher layer signaling. The terminal determinesfour TCI states of the four PDSCHs according to the index sequence.

For another example, M=2 and N=8, the candidate index sequence may be{0, 1, 0, 1, 0, 1, 0, 1}, {0, 0, 0, 0, 0, 0, 0, 0}, or {1, 1, 1, 1, 1,1, 1, 1}.

Manner 2: The length of the index sequence is M, the M TCI statesindicated by the index sequence correspond to the N PDSCHs circularly.If N<M, then the first N TCI states indicated by the index sequence canbe in one-to-one correspondence with the multiple PDSCHs, and theterminal can determine the TCI states of the N PDSCHs according to thefirst N TCI states. Specifically, the n-th PDSCH in the N PDSCHscorresponds to a TCI state with index value m in the M TCI states, wherem is the k-th index value in the index sequence, and k=[(n−1) mod M+1].

For example, M=2 and N=4, the candidate index sequence can be {0, 1},{0, 0}, or {1, 1}, and the network device can inform the terminal inadvance through higher layer signaling that the index sequence used forthe current PDSCH transmission is {0, 1}. As such, the terminal candetermine that the index values of TCI states corresponding to N PDSCHsare {0, 1, 0, 1}, and then determine a TCI state of a PDSCH from the MTCI states.

For example, M=3 and N=2, the candidate index sequence can be {0, 1, 2},{0, 0, 0}, {0, 0, 1}, {0, 1, 1}, or {1, 1, 1}, the network device caninform the terminal in advance through higher layer signaling that theindex sequence used for the current PDSCH transmission is {0, 1, 2}. Aasuch, the terminal determines that index values of TCI statescorresponding to N PDSCHs are {0, 1}, and then determines a TCI state ofa PDSCH from the M TCI states.

For example, M=3 and N=8, the candidate index sequence can be {0, 1, 2},{0, 0, 0}, {0, 0, 1}, {0, 1, 1}, or {1, 1, 1}, the network device caninform the terminal in advance through higher layer signaling that theindex sequence used for the current PDSCH transmission is {0, 1, 2}. Assuch, as illustrated in FIG. 5b , the terminal determines that the indexvalues of the TCI states corresponding to the N PDSCHs are {0, 1, 2, 0,1, 2, 0, 1}, and then determines a TCI state of a PDSCH from the M TCIstates.

Manner 3: The length of the index sequence is equal to the fixed valueX, and the X TCI states indicated by the index sequence correspond tothe N PDSCHs circularly. Here, if NIX, then the first N TCI statesindicated by the index sequence can be in one-to-one correspondence withthe multiple PDSCHs, and the terminal can determine the TCI states ofthe N PDSCHs according to the first N TCI states. Specifically, the n-thPDSCH in the N PDSCHs corresponds to a TCI state with index value m inthe X TCI states. m is the k-th index value in the index sequence, andk=[(n−1) mod X+1]. In the following, suppose X=2.

For example, X=2 and N=4, the candidate index sequence can be {0, 1},{0, 0}, or {1, 1}, the network device can inform the terminal in advancethrough higher layer signaling that the index sequence used for thecurrent PDSCH transmission is {0, 1}. As such, as illustrated in FIG. 5c, the terminal determines that the index values of the TCI statescorresponding to the N PDSCHs are {0, 1, 0, 1}, and then determines aTCI state of a PDSCH from the M TCI states.

For example, X=2 and N=8, the candidate index sequence can be {0, 1},{0, 0}, or {1, 1}, the network device can inform the terminal in advancethrough higher layer signaling that the index sequence used for thecurrent PDSCH transmission is {1, 0}. As such, the terminal determinesthat the index values of TCI states corresponding to N PDSCHs are {1, 0,1, 0, 1, 0, 1, 0}, and then determines a TCI state of a PDSCH from the MTCI states.

At block 506, the terminal detects the multiple PDSCHs according to theTCI state which is applied to each of the multiple PDSCHs.

Suppose a first PDSCH in the multiple PDSCHs corresponds to a first TCIstate, and the first TCI state contains QCL Type B and a correspondingfirst CSI-RS resource ID as well as QCL Type D and a correspondingsecond CSI-RS resource ID, where the first CSI-RS resource ID indicatesa first CSI-RS resource, and the second CSI-RS resource ID indicates asecond CSI-RS resource.

In one possible implementation, the terminal assumes that the firstPDSCH and a channel through which the signal on the first CSI-RSresource passes have the same Doppler shift and Doppler spread. Here,the terminal can adopt the Doppler shift and Doppler spread used toreceive the CSI-RS on the first CSI-RS resource to detect the firstPDSCH. Similarly, the terminal can use the receive-beam used to receivethe CSI-RS signal on the second CSI-RS resource to receive the firstPDSCH.

For each of the multiple PDSCHs, detection can be performed by theterminal according to the TCI state of the PDSCH and the operationsdescribed above.

FIG. 6 is a method for downlink data transmission. The method isapplicable to the above communication system and includes the followingoperations.

At block 601, the network device decides to transmit PDSCH by K TRPs,and repetition of the PDSCH is performed across multiple slots toimprove transmission reliability. The number (N) of repetition isnotified to the terminal through higher layer signaling, N=2, 4, 8, andK is a positive integer.

At block 602, the network device determines a beam(s) used fortransmitting the PDSCH by the K TPRs and K corresponding TCI states.Here, the TCI states are determined according to the TRP.

AT block 603, the network device transmits downlink DCI for schedulingmultiple PDSCHs which are transmitted repeatedly. The DCI contains TCIstate indication for indicating the K TCI states.

At block 604, the terminal receives the number (N) of PDSCH repetitionwhich is notified by the network device through RRC signaling.

At block 605, the terminal receives downlink DCI for scheduling the NPDSCH transmissions, the DCI contains TCI state indication forindicating the K TCI states.

Here, suppose the multiple PDSCHs are transmitted across N consecutiveslots. The method of this implementation is also applicable toconsecutive PDSCH transmission occasions based PDSCH repetition.

At block 606, the terminal determines the TCI state which is applied toeach of the multiple PDSCHs according to the K TCI states indicated bythe TCI state indication.

Specifically, the terminal determines the TCI state which is applied toeach PDSCH from the K TCI states according to the redundancy versionconfiguration(s) of the multiple PDSCHs.

The redundancy version configuration(s) of the multiple PDSCHs can beredundancy version indication(s) contained in the DCI used forscheduling the PDSCH, or can be the actual redundancy version(s) used bythe multiple PDSCHs.

Manner 1: The terminal determines an index sequence corresponding toredundancy version indication contained in DCI, and determines the TCIstate which is applied to each PDSCH from the K TCI states.

For example, the terminal determines the index sequence according to thevalue of the redundancy version indication and a correspondence betweenvalues of the redundancy version indication and index sequences. Thecorrespondence can be agreed between the terminal and the network devicein advance, such as that illustrated in Table. 1, where K=2:

TABLE 1 Value of the redundancy version indication field in DCI Indexsequence 00 {0, 0} 01 {0, 1} 10 {1, 1} 11 Reserved

The redundancy version indication can be used to indicate one of fourredundancy version IDs {0, 1, 2, 3}. The terminal determines the indexsequence corresponding to the redundancy version ID. The correspondencebetween values of the redundancy version indication and index sequencescan be agreed between the terminal and the network device in advance,such as that illustrated in Table. 2, where K=2:

TABLE 2 Redundancy version ID indicated by the redundancy versionindication Index sequence 0 {0, 0} 2 {0, 1} 3 {1, 0} 1 {1, 1}

The manner in which the TCI state which is applied to each PDSCH isdetermined according to the index sequence is similar to that of FIG. 5a, and will not be repeated herein again.

Manner 2: The terminal determines the TCI state of the PDSCH accordingto the redundancy version used by each of the multiple PDSCHs and acorrespondence between redundancy versions and TCI states.

The redundancy version used by one PDSCH can be one of {0, 1, 2, 3}.

The correspondence between redundancy versions and TCI states can beagreed between the terminal and the network device in advance, forexample, if K=2, then indexes of TCI states corresponding to PDSCHs,which adopt redundancy versions {0, 2, 3, 1}, are respectively {0, 1, 0,1}, {0, 1, 1, 0}, or {0, 0, 1, 1} in the K TCI states.

At block 607, the terminal performs detection on the multiple PDSCHsaccording to the TCI state which is applied to each of the multiplePDSCHs.

For example, a first PDSCH in the multiple PDSCHs corresponds to a firstTCI state, and the first TCI state contains QCL Type C and acorresponding first SSB index as well as QCL Type D and correspondingfirst CSI-RS resource ID, the first SSB index indicates the first SSB,and the first CSI-RS resource ID indicates the first CSI-RS resource.

In one possible implementation, the terminal can assume that the firstPDSCH and the channel through which the signal on the first SSB passeshave the same Doppler shift and average delay. As such, the terminal candetect the first PDSCH by using the Doppler shift and average delay thatare used to receive the signal on the first SSB.

The terminal can receive the first PDSCH by adopting the receive-beamthat is used to receive the CSI-RS on the first CSI-RS resource.

In this disclosure, for each of multiple PDSCHs, the terminal canperform detection according to the TCI state of the PDSCH and the abovemethods.

FIG. 7 is a structural diagram of a network device. As illustrated inFIG. 7, the network device includes a processor 710, a memory 720, atransceiver 730. One and more programs 721 are stored in the memory 720and are configured to be executed by the processor 710. The programsinclude instructions for performing the following steps: determining aTCI state which is applied to each of multiple PDSCHs according to atleast one of a beam and a TRP used for transmitting each PDSCH.

As such, the terminal can determine the TCI state which is applied toeach of multiple PDSCHs (or multiple repetitions of one PDSCH)transmitting the same data from multiple TCI states configured by thenetwork device, and can switch flexibly between multiple TCI states. Thecommunication system can obtain significant diversity gain with lesssignaling overhead, and the reliability of downlink PDSCH transmissioncan be improved.

In one possible implementation, in the multiple PDSCHs, PDSCHstransmitted by using different beams or by different TRPs correspond todifferent TCI states, and/or, PDSCHs transmitted by using a same beam orby a same TRP correspond to a same TCI state.

In one possible implementation, the programs further includeinstructions for performing the following operations: transmitting DCIfor scheduling the multiple PDSCHs, the DCI contains TCI stateindication for indicating the TCI state which is applied to each of themultiple PDSCHs, and the multiple PDSCHs carry the same data.

In one possible implementation, the multiple PDSCHs correspond tomultiple TCI states.

In one possible implementation, the programs further includeinstructions for performing the following operations: transmitting themultiple PDSCHs according to the beam or the TRP used for transmittingeach of the multiple PDSCHs.

FIG. 8 is a structural diagram illustrating a terminal. As illustratedin FIG. 8, the terminal includes a processor 810, a memory 820, and acommunication interface 830. One or more programs are stored in thememory 820 and configured to be processed by the processor 810. Theprograms include instructions for performing the following steps:receiving DCI for scheduling multiple PDSCHs, where the DCI contains TCIstate indication; determining the TCI state which is applied to each ofthe multiple PDSCHs from the at least one TCI state indicated by the TCIstate indication.

As such, the terminal can determine the TCI state which is applied toeach of multiple PDSCHs (or multiple repetitions of one PDSCH)transmitting the same data from multiple TCI states configured by thenetwork device, and can switch flexibly between multiple TCI states. Thecommunication system can obtain significant diversity gain with lesssignaling overhead, and the reliability of downlink PDSCH transmissioncan be improved.

In one possible implementation, the multiple PDSCHs carry the same data.In one possible implementation, the multiple PDSCHs are transmittedacross consecutive slots, across consecutive PDSCH transmissionoccasions, or in a single slot. In one possible implementation, themultiple PDSCHs are transmitted based on at least one of: a samedemodulation reference signal (DMRS) port, a same orthogonal frequencydivision multiplexing (OFDM) symbol, or a same modulation and codingscheme (MCS) and a same hybrid automatic repeat request (HAQR) process.In one possible implementation, the at least one TCI state is multipleTCI states. In one possible implementation, in terms of determining theTCI state which is applied to each of the multiple PDSCHs from at leastone TCI state indicated by the TCI state indication, the instructions inthe program are configured to perform the following operations:determining the TCI state which is applied to each PDSCH from the atleast one TCI state according to a rule agreed with the terminal device.

In one possible implementation, the number of the multiple PDSCHs is N,the number of the at least one TCI state is K, where N and K arepositive integers.

The rule includes at least one of: the multiple PDSCHs are in one-to-onecorrespondence with the at least one TCI state, when N=K; the first NTCI sates in the at least one TCI state correspond to the N PDSCHs, andthe N PDSCHs are in one-to-one correspondence with the first N TCIstates, when N<K; the n-th PDSCH in the multiple PDSCHs corresponds tothe k-th TCI state in the at least one TCI state, and k=[(n−1) mod K+1],when N>K; the n-th PDSCH in the multiple PDSCHs corresponds to the k-thTCI state in the at least one TCI state, and k=[n/m], when N=K*m and mis an integer greater than 1.

In one possible implementation, in terms of determining the TCI statewhich is applied to each of the multiple PDSCHs from the at least oneTCI state indicated by the TCI state indication, the instructions in theprogram are configured to perform the following operations: determiningthe TCI state which is applied to each PDSCH from at least one TCI stateaccording to an index sequence configured by the network device throughhigher layer signaling.

In one possible implementation, each index value in the index sequenceis for indicating an index of a TCI state in the at least one TCI state.In one possible implementation, the length of the index sequence isequal to the number of the multiple PDSCHs, and the TCI states indicatedby the index sequence are in one-to-one correspondence with the multiplePDSCHs. In terms of determining the TCI state which is applied to eachPDSCH from the at least one TCI state according to the index sequenceconfigured by the network device through higher layer signaling, theinstructions in the programs are configured to perform the followingoperations: determining the TCI state which is applied to each PDSCHaccording to the TCI states indicated by the index sequence and thecorrespondence between the TCI states and the multiple PDSCHs.

In one possible implementation, the index sequence has a length equal tothe number of the at least one TCI state or equal to a fixed value, TCIstates indicated by the index sequence correspond to the multiple PDSCHscircularly, or the first N TCI states in the TCI states indicated by theindex sequence are in one-to-one correspondence with the multiplePDSCHs, where N is the number of the multiple PDSCHs. In terms ofdetermining the TCI state which is applied to each of the multiplePDSCHs from the at least one TCI state according to the index sequenceconfigured through higher layer signaling, the instructions of theprograms are configured to perform the following operations: determiningthe TCI state which is applied to each of the multiple PDSCHs accordingto the TCI states indicated by the index sequence and the correspondencebetween the TCI states and the multiple PDSCHs.

In one possible implementation, the fixed value is 2.

In one possible implementation, the n-th PDSCH in the multiple PDSCHscorresponds to a TCI state with an index value m in the at least one TCIstate, wherein m is the k-th index value in the index sequence, k=[(n−1)mod K+1], and K represents the length of the index sequence.

In one possible implementation, in terms of determining the TCI statewhich is applied to each of multiple PDSCHs from the at least one TCIstate indicated by the TCI state indication, the instructions in theprograms are configured to perform the following operations: determiningthe TCI state which is applied to each PDSCH from at least one TCI stateaccording to the redundancy version configuration(s) of the multiplePDSCHs.

In one possible implementation, in terms of determining the TCI statewhich is applied to each PDSCH from at least one TCI state according tothe redundancy version configuration(s) of the multiple PDSCHs, theinstructions in the programs are configured to perform the followingoperations: determining the index sequence corresponding to redundancyversion indication contained in the DCI, and determining the TCI statewhich is applied to each PDSCH from the at least one TCI state accordingto the index sequence; or determining the TCI state which is applied toeach PDSCH according to the redundancy version used by each of multiplePDSCHs and a correspondence between redundancy versions and TCI states.

In one possible implementation, the programs further includeinstructions for performing the following operations: detecting themultiple PDSCHs according to the TCI state which is applied to each ofthe multiple PDSCHs.

In one possible implementation, in terms of detecting the multiplePDSCHs according to the TCI state which is applied to each of themultiple PDSCHs, the instructions in the programs are configured toperform the following operations: detecting each of the multiple PDSCHsby detecting large-scale parameters used by a quasi co-location (QCL)reference signal contained in the TCI state which is applied to each ofthe multiple PDSCHs, according to the QCL reference signal and a QCLtype contained in the TCI state which is applied to each of the multiplePDSCHs, wherein the large-scale parameter is a large-scale parameterindicated by the QCL type.

Implementations are mainly introduced from the perspective ofinteraction between network elements. It is understandable that in orderto achieve the above functions, the terminal and network device mayinclude respective hardware structures and/or software modules toperform the respective functions. It is easy for those skilled in theart to realize that in combination with the units and algorithm steps ofeach implementation described above, the disclosure can be implementedin the form of hardware or a combination of hardware and computersoftware. Whether a specific function is implemented by hardware orcomputer software driven hardware depends on the specific applicationand design constraints of the technical solution. Professionaltechnicians can use different methods to achieve the described functionsof each specific application, but such implementation shall not beconsidered beyond the scope of the disclosure.

Functional units of the terminal and the network device can be dividedaccording to the above method implementations. For example, eachfunctional unit can be divided according to each function, and two ormore functions can be integrated into one processing unit. Theintegrated unit can be realized in the form of hardware or softwareprogram module. It should be noted that the division of units inimplementations is schematic, which is only a logical function division,and there can be another division mode in actual implementation.

In the case of adopting integrated units, FIG. 9 illustrates a possiblefunctional unit block diagram of the network device involved in theabove implementation. The network device functions as a first networkdevice. The network device 900 includes a processing unit 902 and acommunication unit 903. The processing unit 902 is configured to controland manage actions of the network device. For example, the processingunit 902 is configured to enable the network device to perform step 201in FIG. 2, steps 401-403 in FIG. 4a , steps 501-503 in FIG. 5a , steps601-603 in FIG. 6 and/or other processes for implement techniquesdescribed herein. The communication unit 903 is configured to enablecommunication between the network device and other devices, such as thecommunication between the network device and the terminal. The networkdevice may further include a storage unit 901, which is configured tostore program codes and data of the network device.

The processing unit 902 can be a processor or controller, and thecommunication unit 903 can be a transceiver, a transceiver circuit, aradio frequency (RF) chip, the storage unit 901 can be a memory.

The processing unit 902 is configured to determine a TCI state which isapplied to each of multiple PDSCHs according to at least one of a beamand a TRP used for transmitting each PDSCH.

In one possible implementation, in the multiple PDSCHs, PDSCHstransmitted by using different beams or by different TRPs correspond todifferent TCI states, and/or, in the multiple PDSCHs, PDSCHs transmittedby using a same beam or by a same TRP correspond to a same TCI state.

In one possible implementation, the processing unit 902 is furtherconfigured to send DCI for scheduling the multiple PDSCHs through thecommunication unit 903. The DCI contains TCI state indication forindicting the TCI state which is applied to each of the multiple PDSCHs,and the multiple PDSCHs carry the same data.

In one possible implementation, the TCI state corresponding to themultiple PDSCHs includes multiple TCI states.

In one possible implementation, the processing unit 902 is furtherconfigured to transmit the multiple PDSCHs through the communicationunit 903 according to the beam or TRP for transmitting each PDSCH.

In case that the processing unit 902 is a processor, the communicationunit 903 is a communication interface, and the storage unit is a memory,the network device used herein can be the network device illustrated inFIG. 7.

In the case of adopting integrated units, FIG. 10 illustrates a possiblefunctional unit block diagram of the terminal involved in the aboveimplementation. The terminal 1000 includes a processing unit 1002 and acommunication unit 1003. The processing unit 1002 is configured tocontrol and manage actions of the terminal. For example, the processingunit 1002 is configured to enable the terminal to perform steps 301-302in FIG. 3, steps 404-407 in FIG. 4a , steps 504-506 in FIG. 5a , steps604-607 in FIG. 6 and/or other processes for implement techniquesdescribed herein. The communication unit 1003 is configured to enablecommunication between the terminal and other devices, such as thecommunication between the network device and the terminal. The networkdevice may further include a storage unit 1001, which is configured tostore program codes and data of the terminal.

The processing unit 1002 may be a processor or controller, such as acentral processing unit (CPU), a general purpose processor, a digitalsignal processor (DSP), an application-specific integrated circuit(ASIC), a field programmable gate array (FPGA), or other programmablelogic devices, transistor logic devices, hardware components, or anycombination thereof. The processing unit 1002 can implement or executevarious exemplary logical boxes, modules and circuits described incombination with the contents of the disclosure. The processor may alsobe a combination of computing functions, for example, including acombination of one or more microprocessor, a combination of DSP andmicroprocessor, etc. The communication unit 1003 can be a transceiver, atransceiver circuit, etc., and the storage unit 1001 can be memory.

The processing unit 1002 is configured to receive, through thecommunication unit 1003, DCI for scheduling multiple PDSCHs, where theDCI contains TCI state indication, and determine a TCI state which isapplied to each of the multiple PDSCHs according to at least one TCIstate indicated by the TCI state indication.

In one possible implementation, the multiple PDSCHs carry the same data.In one possible implementation, the multiple PDSCHs are transmittedacross consecutive slots, across consecutive PDSCH transmissionoccasions, or in a single slot. In one possible implementation, themultiple PDSCHs are transmitted based on at least one of: a samedemodulation reference signal (DMRS) port, a same orthogonal frequencydivision multiplexing (OFDM) symbol, or a same modulation and codingscheme (MCS) and a same hybrid automatic repeat request (HAQR) process.In one possible implementation, the at least one TCI state includesmultiple TCI states. In one possible implementation, in terms ofdetermining the TCI state which is applied to each of multiple PDSCHsfrom at least one TCI state indicated by the TCI state indication, theprocessing unit 1002 is configured to: determine the TCI state which isapplied to each of the multiple PDSCHs from the at least one TCI stateaccording to a rule agreed with a network device. In one possibleimplementation, the number of the multiple PDSCHs is N, the number ofthe at least one TCI state is K, N and K are positive integers.

The rule includes at least one of: the multiple PDSCHs are in one-to-onecorrespondence with the at least one TCI state, when N=K; the first NTCI sates in the at least one TCI state correspond to the N PDSCHs, andthe N PDSCHs are in one-to-one correspondence with the first N TCIstates, when N<K; the n-th PDSCH in the multiple PDSCHs corresponds tothe k-th TCI state in the at least one TCI state, and k=[(n−1) mod K+1],when N>K; the n-th PDSCH in the multiple PDSCHs corresponds to the k-thTCI state in the at least one TCI state, and k=[n/m], when N=K*m and mis an integer greater than 1.

In one possible implementation, in terms of determining the TCI statewhich is applied to each of multiple PDSCHs from at least one TCI stateindicated by the TCI state indication, the processing unit 1002 isconfigured to: determine the TCI state which is applied to each of themultiple PDSCHs from the at least one TCI state according to an indexsequence configured through higher layer signaling. In one possibleimplementation, each index value in the index sequence is used toindicate the index of one TCI state in the at least one TCI state. Inone possible implementation, the length of the index sequence is equalto the number of the multiple PDSCHs, and the TCI states indicated bythe index sequence are in one-to-one correspondence with the multiplePDSCHs. In terms of determining the TCI state which is applied to eachof the multiple PDSCHs from the at least one TCI state according to anindex sequence configured through higher layer signaling, the processingunit 1002 is configured to: determine the TCI state which is applied toeach of the multiple PDSCHs according to the TCI states indicated by theindex sequence and the correspondence between index sequences andPDSCHs. In one possible implementation, the length of the index sequenceis equal to the number of the at least one TCI state or equal to a fixedvalue. TCI states indicated by the index sequence correspond to themultiple PDSCHs circularly, or the first N TCI states in the TCI statesindicated by the index sequence are in one-to-one correspondence withthe multiple PDSCHs, where Nis the number of the multiple PDSCHs. Interms of determining the TCI state which is applied to each PDSCH fromat least one TCI state according to the index sequence configured by thenetwork device through higher layer signaling, the processing unit 1002is configured to: determine the TCI state which is applied to each PDSCHaccording to the TCI state indicated by the index sequence and thecorrespondence between the index sequences and PDSCHs. In one possibleimplementation, the fixed value is 2.

In one possible implementation, the n-th PDSCH in the multiple PDSCHscorresponds to a TCI state with index value m in the at least one TCIstate, m is the k-th index value in the index sequence, k=[(n−1)modK+1], K is the length of the index sequence.

In one possible implementation, in terms of determining the TCI statewhich is applied to each of the multiple PDSCHs from the at least oneTCI state indicated by the TCI state indication, the processing unit1002 is configured to: determine the TCI state which is applied to eachof the multiple PDSCHs from the at least one TCI state according to aredundancy version configuration(s) of the multiple PDSCHs.

In one possible implementation, in terms of determining the TCI statewhich is applied to each of the multiple PDSCHs from the at least oneTCI state according to redundancy version configuration(s) of themultiple PDSCHs, the processing unit 1002 is configured to: determine anindex sequence corresponding to redundancy version indication containedin the DCI according to the redundancy version indication, and determinethe TCI state which is applied to each of the multiple PDSCHs from theat least one TCI state according to the index sequence; or determine theTCI state which is applied to each of the multiple PDSCHs according to aredundancy version used by each of the multiple PDSCHs and acorrespondence between redundancy versions and TCI states.

In one possible implementation, the processing unit 1002 is furtherconfigured to: detect the multiple PDSCHs according to the TCI statewhich is applied to each of the multiple PDSCHs.

In one possible implementation, in terms of detecting the multiplePDSCHs according to the TCI state which is applied to each of themultiple PDSCHs, the processing unit 1002 is configured to: detect eachof the multiple PDSCHs by detecting large-scale parameters used by aquasi co-location (QCL) reference signal contained in the TCI statewhich is applied to each of the multiple PDSCHs, according to the QCLreference signal and a QCL type contained in the TCI state which isapplied to each of the multiple PDSCHs, where the large-scale parameteris a large-scale parameter indicated by the QCL type.

When the processing unit 1002 is a processor, the communication unit1003 is a communication interface, and the storage unit 1001 is amemory, the terminal device used herein can be the terminal deviceillustrated in FIG. 8.

Implementations further provide a computer readable storage medium,which is configured to store computer programs for electronic dataexchange, where the computer programs are operable with a computer toperform all or part of the steps in the method performed by the networkdevice or the terminal.

Implementations further provide a computer program product, whichincludes non-transitory computer readable storage medium storingcomputer programs. The computer programs are operable with a computer toperform all or part of the steps in the method performed by the networkdevice or the terminal. The computer program product can be implementedas a software installation package.

The steps of the method or algorithm described in implementations of thedisclosure can be realized by means of hardware or by means of softwareinstructions executed by the processor. Software instructions can becomposed of corresponding software modules, which can be stored inrandom access memory (RAM), flash memory, read only memory (ROM),erasable programmable read only memory (EPROM), electrically erasableprogrammable read only memory (EEPROM), register Hard disk, mobile harddisk, CD-ROM or any other form of storage medium well known in the art.An exemplary storage medium is coupled to a processor, such that theprocessor can read information from the storage medium or write datainto the storage medium. Alternatively, the storage medium can be partof the processor. The processor and the storage medium can be located inthe ASIC. The ASCI can be located in an access network device, a targetnetwork device, or a core network device. The processor and the storagemedium can also exist as discrete components in the access networkdevice, the target network device, or the core network device.

All or part of the above implementations can be implemented throughsoftware, hardware, firmware, or any other combination thereof. Whenimplemented by software, all or part of the above implementations can beimplemented in the form of a computer program product. The computerprogram product includes one or more computer instructions. When thecomputer instructions are applied and executed on a computer, all orpart of the operations or functions of the implementations of thedisclosure are performed. The computer can be a general-purposecomputer, a special-purpose computer, a computer network, or otherprogrammable apparatuses. The computer instruction can be stored in acomputer readable storage medium, or transmitted from one computerreadable storage medium to another computer storage medium. For example,the computer instruction can be transmitted from one website, computer,server, or data center to another website, computer, server, or datacenter in a wired manner or in a wireless manner. Examples of the wiredmanner can be a coaxial cable, an optical fiber, a digital subscriberline (DSL), etc. The wireless manner can be, for example, infrared,wireless, microwave, etc. The computer readable storage medium can beany computer accessible usable medium or data storage device such as aserver, a data center, or the like which is integrated with one or moreusable media. The usable medium can be a magnetic medium (such as a softdisc, a hard disc, or a magnetic tape), an optical medium (such as adigital video disc (DVD)), or a semiconductor medium (such as a solidstate disk (SSD)), etc.

The specific implementations described above further illustrates thepurpose, technical schemes, and beneficial effects of the disclosure. Itshould be understood that the above is only specific implementations ofthe disclosure and is not intended to limit the protection scope of thedisclosure. Any modification, equivalent replacement, improvement, etc.based on the technical solution of the implementations shall be includedin the protection scope of the disclosure.

What is claimed is:
 1. A method for downlink data transmission,comprising: receiving, by a terminal, one downlink control information(DCI) for scheduling multiple physical downlink shared channels(PDSCHs), wherein the multiple PDSCHs carry same data, wherein the DCIcontains transmission configuration indicator (TCI) state indication;and determining, by the terminal, TCI states comprising a first TCIstate and a second TCI state which are applied to the multiple PDSCHsaccording to the TCI state indication; wherein a number of the multiplePDSCHs N are equal or greater than a quality of TCI states K and Kequals 2; when N>K, the n-th PDSCH in the multiple PDSCHs corresponds toone of the first TCI state and the second TCI state, and k=[(n−1) modK+1], when N=K, the multiple PDSCHs are in one-to-one correspondencewith the first TCI state and the second TCI state.
 2. The method ofclaim 1, wherein the multiple PDSCHs are transmitted across consecutiveslots, across consecutive PDSCH transmission occasions, or in a singleslot.
 3. The method of claim 1, wherein the multiple PDSCHs aretransmitted based on at least one of: a same demodulation referencesignal (DMRS) port, a same orthogonal frequency division multiplexing(OFDM) symbol, or a same modulation and coding scheme (MCS) and a samehybrid automatic repeat request (HAQR) process.
 4. The method of claim1, wherein determining, by the terminal, TCI states comprising a firstTCI state and a second TCI state which are applied to the multiplePDSCHs according to the TCI state indication comprises: determining, bythe terminal, the first TCI state and the second TCI state which areapplied to the multiple PDSCHs according to an index sequence configuredby a network device through higher layer signaling.
 5. The method ofclaim 4, wherein the K TCI states are circularly applied to the NPDSCHs.
 6. The method of claim 5, wherein when N=2, the index sequenceof the TCI states corresponding to the two PDSCHs is {0, 1}.
 7. Themethod of claim 5, wherein when N=4, the index sequence of the TCIstates corresponding to the four PDSCHs is {0, 1, 0, 1}.
 8. The methodof claim 5, wherein when N=8 the index sequence of the TCI statescorresponding to the eight PDSCHs is {0, 1, 0, 1, 0, 1, 0, 1}.
 9. Themethod of claim 4, wherein the K TCI states are applied to the N PDSCHsin sequence.
 10. The method of claim 9, wherein when N=2, the indexsequence of the TCI states corresponding to the two PDSCHs is {0, 1}.11. The method of claim 9, wherein when N=4, the index sequence of theTCI states corresponding to the four PDSCHs is {0,0,1, 1}.
 12. Aterminal, comprising: a processor; a transceiver; and a memory storingone or more programs which, when executed by the processor, are operablewith the transceiver to receive DCI for scheduling multiple PDSCHs,wherein the multiple PDSCHs carry same data, wherein the DCI containsTCI state indication, and operable with the processor to determine TCIstates comprising a first TCI state and a second TCI state which areapplied to the multiple PDSCHs according to the TCI state indication;wherein a number of the multiple PDSCHs N are equal or greater than aquality of TCI states K and K equals 2; when N>K, the n-th PDSCH in themultiple PDSCHs corresponds to one of the first TCI state and the secondTCI state, and k=[(n−1) mod K+1], when N=K, the multiple PDSCHs are inone-to-one correspondence with the first TCI state and the second TCIstate.
 13. The terminal of claim 12, wherein the processor configured todetermine TCI states comprising a first TCI state and a second TCI statewhich are applied to the multiple PDSCHs according to the TCI stateindication is configured to: determine the first TCI state and thesecond TCI state which are applied to the multiple PDSCHs according toan index sequence configured by a network device through higher layersignaling.
 14. A non-transitory computer readable storage medium,configured to store computer programs, wherein the computer programs areoperable with a computer to: receive, by a terminal, one DCI forscheduling multiple PDSCHs, wherein the multiple PDSCHs carry same data,wherein the DCI contains TCI state indication; and determine, by theterminal, TCI states comprising a first TCI state and a second TCI statewhich are applied to the multiple PDSCHs according to the TCI stateindication; wherein a number of the multiple PDSCHs N are equal orgreater than a quality of TCI states K and K equals 2; when N>K, then-th PDSCH in the multiple PDSCHs corresponds to one of the first TCIstate and the second TCI state, and k=[(n−1) mod K+1], when N=K, themultiple PDSCHs are in one-to-one correspondence with the first TCIstate and the second TCI state.